The Cell Culture and Physiology Core will be a centralized facility that will provide primary alveolar epithelial type 2 cells and secondary alveolar epithelial cell lines to each of the five projects within the program project, as well as conduct physiology experiments utilizing the isolated perfused lung model. Centralization of the cell culture facilities will ensure that a continuous supply of high quality and purity alveolar epithelial cells is available to each of the five projects. The core will characterize the primary and secondary alveolar epithelial cells used in this program project. The cell culture facility personnel have extensive experience in the isolation of alveolar epithelial type 2 cells, as well as general cell culture techniques. The consolidation of the cell culture facilities will provide an economical means of isolating and culturing alveolar epithelial cells. The core will also conduct physiology experiments to measure the rate of alveolar fluid reabsorption and active Na+ transport utilizing the isolated-perfused lung model. Centralization of the physiology experiments will reduce the cost of conducting these experiments within the individual projects and more importantly maintain the precision and accuracy in which these experiments are conducted.